Written by Peter Liu
Spoon Feed
In the Atherosclerosis Risk in Communities (ARIC) Study, lifetime risk of dementia from age 55 to 95 was estimated at 42%, with risk rising sharply after 75 years of age.
Lifetime dementia risk is high after age 75
The Atherosclerosis Risk in Communities (ARIC) study is a prospective cohort of 15,043 participants from four US communities in North Carolina, Mississippi, Minnesota, and Maryland. Dementia was diagnosed in several ways, including cognitive testing (24%), phone interviews (49%), and review of hospital and death records (27%). There were several highlights:
- The lifetime risk of dementia from age 55 to 95 was estimated at 42% (95%CI 41–43), with higher risks among women (48%), Black adults (44%), and APOE ε4 carriers (up to 59%).
- The risk of dementia from 55 years old to 75 years old was low (3.9%), but rose sharply after 75.
- Median age of dementia diagnosis was 81 years old. Dementia occurred at earlier ages for APOE ε4 carriers (median age: 79 years for two copies, 81 years for one copy and 82 years for no copies).
- The number of new annual dementia cases in the U.S. was projected to nearly double from 514,000 in 2020 to 1 million in 2060.
How does this change my practice?
Care for patients with dementia remains a large part of most internal medicine practices, and counseling of patients and caregivers is often the mainstay of disease-specific care. Results from the ARIC study allow providers to normalize the profound experience of dealing with dementia and put the strong, myriad emotions and frustrations of patients and families in the context of many others who face the same challenges. Knowledge of the APOE ε4 risk factor, and understanding the magnitude of its impact in dementia risk, is also frequently helpful in this context.
Source
Lifetime risk and projected burden of dementia. Nat Med. 2025 Jan 13. doi: 10.1038/s41591-024-03340-9. Epub ahead of print. PMID: 39806070
